Just imagine what America would be like if the Axis powers had won the Second World War... Would you join the resistance? Work with the occupiers? Keep your head down? Or hunt out curious documentary films that seem to show an alternate world where the Allies won?

Season one of 'The Man in the High Castle', Ridley Scott’s adaptation of Philip K Dick’s sci-fi novel, examined all these possibilities in Amazon’s most-streamed original series to date.

Season two, released on Amazon on 16 December, picks up the story.

Set in the US in 1962, it depicts a continent divided between the Japanese and the Germans, and the drama follows a handful of young activists as they try to sabotage the occupation using odd films depicting an alternative reality. Swaggering triumphantly into the heart of their efforts is Rufus Sewell, by turns chilling and confusing as SS Obergrupenführer John Smith.

Many actors might baulk at the idea of playing a Nazi and even Sewell, who’d worked with Scott before on 'Tristan & Isolde', 'The Pillars of the Earth' and 'Killing Jesus', had reservations. “When I read the pilot – and I knew that Smith wasn’t originally in Philip K Dick’s book – I was a bit worried that he was going to be a one-dimensional villain,” he explains. “At the beginning he’s marching up and down corridors a lot and everyone he speaks to is hanging upside down from a chain. It’s not a good start. So I needed to be reassured that he had a complex life.”

It was episode two that convinced him. “There was a scene with his family where if you forget the fact that he’s wearing a Nazi uniform he’s actually not being a bad dad,” he gives a boyish grin. “To explore the idea that he was, in a weird twisted way, a Nazi everyman... someone who would have been a good guy if things had panned out differently in 1945 but who was brutalised by a system. Well, that was hugely interesting for me.”

Sewell did his research into Nazi Germany after taking the role and found this exact dichotomy in real life. “Decent people did terrible things – that’s what happened in Germany,” he points out. “It’s good to show the two sides of the coin.”

Where season one cunningly used imagery of Swastika flags draping Times Square, season two plays with iconic newsreel footage: Marilyn Monroe singing “Happy Birthday” to JFK becomes a serenade to an elderly Adolf Hitler.

“The second series is all about conflict – internal and external,” Sewell explains. “In life I’m done with pain and drama – but the more they can chuck at this guy, the more interesting it becomes.”

'The Man in the High Castle' Season 2 is out now on Amazon Prime Video